The present invention is concerned with improvements in or relating to ventilation tiles and is particularly, although not exclusively, concerned with improvements in ventilation tiles which may readily be adapted for use with a wide range of roof tiles, ventilation means and soil pipes.
Hitherto, ventilation tiles, e.g. those tiles on a tiled roof which comprise or consist of means for venting the roof or providing openings for accommodating outlet end portions of soil pipes, have been of manifold shapes and configurations. In general, it has been the usual practice to provide a ventilation tile to suit each shape and configuration of roof tile; thus, "plain" tiles will be complemented by one configuration of ventilation tile and "bold roll", "Roman" or "Double Roman" tiles will each be complemented by an appropriately shaped ventilation tile.
This practice has meant that manufacturers and stockists of such products have had to contend with large stocks of specials in order to meet the requirements of the end users.
British Patent Specification No. 1080837 discloses a roofing element for forming a weatherproof seal between a member, such as a pipe, and a roof from which the member projects. The element comprises a slate-like slab or panel of neoprene or butyl synthetic rubber or the like which may be stiffened by an internal wire mesh and/or stiffening elements applied to edge portions of the element. Such an arrangement will only provide a partial answer to the problems to be overcome for, whereas the slab or panel may be shaped to suit the shape and configuration of adjoining tiles, it will lack the necessary rigidity to enable it to cope with high snow loadings or the high impact loading encountered in hail conditions. In addition, it lacks the side-lock features of a true tile which assist in sealing the roof against the ingress of rainwater and are effective in channeling the rainwater towards the roof gutter.